Lipid profile: causal relationship on cognitive performance in multiple sclerosis?

Although cognitive impairment (CI) is classically associated with aging, it has been proposed that neurological pathologies may increase the risk to suffer CI. Despite the evidence of an elevated prevalence of CI in patients with multiple sclerosis (MS), it is not considered among standard clinical evaluations, due the lack of specialists and time required. The aim of this study was to evaluate if lipid profile is associated with cognitive performance in persons with MS. Twenty patients with MS were evaluated. Montreal Cognitive Assessment (MoCA) was employed to determine cognitive performance. CI was observed in 85% of patients, with memory recall and language as the most affected domains. Despite biomarkers were mostly found within reference values, several correlations were observed. MoCA total score was correlated with cholesterol (r = - 0.468, p = 0.037) and LDL (r = - 0.453, p = 0.045). Visuospatial domain was correlated with LDL (r = - 0.493, p = 0.027). Attention domain correlated with triglycerides (r = - 0.455, p = 0.044) and cholesterol (r = - 0.549, p = 0.012). When the person reaches borderline levels of triglycerides, LDL and cholesterol a decrease in cognitive performance can be observed. The mechanism underlying this association has not been established still, it has been proposed that it could be linked with neuroinflammation, alterations in synapses and in the metabolism of amyloid-ß protein. This study settles the potential importance that lipid profile could have on cognitive performance in MS. Further studies are needed to establish optimal levels and implication of lipid profile in the diagnosis and monitoring of cognitive performance in Mexican people with MS.

Characterization of occupational, demographic and health determinants in Canadian reservists veterans and the relationship with poor self-rated health.

BACKGROUND: Self-rated health is an useful indicator of the general health in specific populations and used to propose interventions after service in the military context. However, there is scarce literature about self- rated health (SRH) in the Canadian Veterans of the Reserve Force and its relationship with demographic, health and occupational characteristics of this specific group. The aims of this research were to determine the SRH in Canadian Reserve Force Veterans and to explore the relationship between demographic, military service and health factors by reserve class. METHODS: Data from the individuals was collected from the Life After Service (LASS) 2013 survey, including Veterans with Reserve Class C (n = 922) and Class A/B (n = 476). Bivariate and multivariate analysis using logistic regression models, were used to assess the association between the demographic characteristics, physical health, mental health, and military service characteristics and the self-rate health by both reserve classes. RESULTS: The overall prevalence of poor SRH in Reserve Class C Veterans was 13.1% (CI:11.08-15.4) and for Reserve Class A/B was 6.9% (CI:5.0-9.1). Different degrees of associations were observed during the bivariate analysis and two different models were produced for each reserve class. Veterans of Reserve Class C showed that being single was (OR = 2.76, CI: 1.47-5.16), being 50-59 years old (OR = 4.6, CI: 1.28-17.11), reporting arthritis (OR = 2.49, CI: 1.33-4.67), back problems (OR = 3.02, CI:1.76-5.16), being obese (OR = 1.96, CI: 1.13-3.38), depression (OR = 2.34, CI: 1.28-4.20), anxiety (OR = 4.11, CI: 2.00-8.42), PTSD (OR = 2.1 CI: 0.98-4.47), PTSD (OR = 20.9, CI:0.98-4.47) and being medically released (OR = 4.48, CI: 2.43-8.24) were all associated with higher odds of poor SRH. The Reserve Class A/B model showed that completing high school (OR = 4.30, CI: 1.37-13.81), reporting arthritis (6.60, CI: 2.15-20.23), diabetes (OR = 11.19, CI: 2.72-46.0), being obese (OR = 3.37, CI: 1.37-8.27), daily smoking (OR = 2.98, CI: 1.05-8.38), having anxiety (OR = 9.8, CI: 3.70-25.75) were associated with higher odds of poor SRH. CONCLUSIONS: These results suggested that the relationship of poor SRH with demographic, health and military occupation domains varied depending on the class on the Reserve Force Service. Different strengths of association showed different risk compositions for both populations. This can be used to better understand the health and well-being of Veterans of the Reserve Force.

Clinical and electrophysiological characteristics of Guillain-Barré syndrome in Colombia.

Despite the wide literature describing the features of Guillain-Barré syndrome (GBS) in different populations worldwide, Colombian data are very scarce. We aim to characterize patients with GBS in a general hospital setting in Colombia. We conducted a retrospective chart review of GBS cases managed at the Hospital Universitario Fundación Santa Fe de Bogotá, from 2011 to 2016. Twenty-three patients were included. The most commonly reported symptoms were paresthesias (65%), pain (61%), proximal (22%) and distal (74%) limb weakness, and facial palsy (30%). 9% of patients had Fisher syndrome and 21% had other variants: Bickerstaff, pharyngeal-cervical-brachial pattern, and facial diplegia. There was a predominance of the demyelinating form (70%), with only 22% of patients presenting with the axonal variants. Our results are concordant with previous studies in Colombia.

A morphological database for 606 Colombian bird species.

Colombia is the country with the highest bird diversity in the world. Despite active research in ornithology, compelling morphological information of most bird species is still sparse. However, morphological information is the baseline to understand how species respond to environmental variation and how ecosystems respond to species loss. As part of a national initiative, the Instituto Alexander von Humboldt in collaboration with 12 Colombian institutions and seven biological collections, measured up to 15 morphological traits of 9,892 individuals corresponding to 606 species: 3,492 from individuals captured in field and 6,400 from museum specimens. Species measured are mainly distributed in high Andean forest, páramo, and wetland ecosystems. Seven ornithological collections in Colombia and 18 páramo complexes throughout Colombia were visited from 2013 to 2015. The morphological traits involved measurements from bill (total and exposed culmen, bill width and depth), wing (length, area, wingspan, and the distance between longest primary and longest secondary), tail (length and shape), tarsus (length), hallux (length and claw hallux), and mass. The number of measured specimens per species was variable, ranging from 1 to 321 individuals with a median of four individuals per species. Overall, this database gathered morphological information for >30% of Colombian bird diversity. No copyright, proprietary, or cost restrictions apply; the data should be cited appropriately when used.

From mesophilic to thermophilic conditions: one-step temperature increase improves the methane production of a granular sludge treating agroindustrial effluents.

OBJECTIVES: To assess the effect of one-step temperature increase, from 35 to 55 °C, on the methane production of a mesophilic granular sludge (MGS) treating wine vinasses and the effluent of a hydrogenogenic upflow anaerobic sludge blanket (UASB) reactor. RESULTS: One-step temperature increase from mesophilic to thermophilic conditions improved methane production regardless of the substrate tested. The biomethane potentials obtained under thermophilic conditions were 1.8-2.9 times higher than those obtained under mesophilic conditions. The MGS also performed better than an acclimated thermophilic digestate, producing 2.2-2.5 times more methane than the digestate under thermophilic conditions. Increasing the temperature from 35 to 55 °C also improved the methane production rate of the MGS (up to 9.4 times faster) and reduced the lag time (up to 1.9 times). Although the temperature increase mediated a decrease in the size of the sludge granules, no negative effects on the performance of the MGS was observed under thermophilic conditions. CONCLUSIONS: More methane is obtained from real agroindustrial effluents at thermophilic conditions than under mesophilic conditions. One-step temperature increase (instead of progressive sequential increases) can be used to implement the thermophilic anaerobic digestion processes with MGS.

Microbial communities from 20 different hydrogen-producing reactors studied by 454 pyrosequencing.

To provide new insight into the dark fermentation process, a multi-lateral study was performed to study the microbiology of 20 different lab-scale bioreactors operated in four different countries (Brazil, Chile, Mexico, and Uruguay). Samples (29) were collected from bioreactors with different configurations, operation conditions, and performances. The microbial communities were analyzed using 16S rRNA genes 454 pyrosequencing. The results showed notably uneven communities with a high predominance of a particular genus. The phylum Firmicutes predominated in most of the samples, but the phyla Thermotogae or Proteobacteria dominated in a few samples. Genera from three physiological groups were detected: high-yield hydrogen producers (Clostridium, Kosmotoga, Enterobacter), fermenters with low-hydrogen yield (mostly from Veillonelaceae), and competitors (Lactobacillus). Inocula, reactor configurations, and substrates influence the microbial communities. This is the first joint effort that evaluates hydrogen-producing reactors and operational conditions from different countries and contributes to understand the dark fermentation process.

Climate analogs can catalyze cross-regional dialogs for US specialty crop adaptation.

Communication theory suggests that interactive dialog rather than information transmission is necessary for climate change action, especially for complex systems like agriculture. Climate analogs-locations whose current climate is similar to a target location's future climate-have garnered recent interest as transmitting more relatable information; however, they have unexplored potential in facilitating meaningful dialogs, and whether the way the analogs are developed could make a difference. We developed climate context-specific analogs based on agriculturally-relevant climate metrics for US specialty crop production, and explored their potential for facilitating dialogs on climate adaptation options. Over 80% of US specialty crop counties had acceptable US analogs for the mid-twenty-first century, especially in the West and Northeast which had greater similarities in the crops produced across target-analog pairs. Western counties generally had analogs to the south, and those in other regions had them to the west. A pilot dialog of target-analog pairs showed promise in eliciting actionable adaptation insights, indicating potential value in incorporating analog-driven dialogs more broadly in climate change communication.

Exploring resistomes and microbiomes in pilot-scale microalgae-bacteria wastewater treatment systems for use in low-resource settings.

Antibiotic resistance genes (ARGs) released into the environment are an emerging human and environmental health concern, including ARGs spread in wastewater treatment effluents. In low-to-middle income countries (LMICs), an alternate wastewater treatment option instead of conventional systems are low-energy, high-rate algal ponds (HRAP) that use microalgae-bacteria aggregates (MABA) for waste degradation. Here we studied the robustness of ARG removal in MABA-based pilot-scale outdoor systems for 140 days of continuous operation. The HRAP system successfully removed 73 to 88 % chemical oxygen demand and up to 97.4 % ammonia, with aggregate size increasing over operating time. Fourteen ARG classes were identified in the HRAP influent, MABA, and effluent using metagenomics, with the HRAP process reducing total ARG abundances by up to 5-fold from influent to effluent. Parallel qPCR analyses showed the HRAP system significantly reduced exemplar ARGs (p < 0.05), with 1.2 to 4.9, 2.7 to 6.3, 0 to 1.5, and 1.2 to 4.8 log-removals for sul1, tetQ, blaKPC, and intl1 genes, respectively. Sequencing of influent, effluent and MABAs samples showed associated microbial communities differed significantly, with influent communities by Enterobacteriales (clinically relevant ARGs carrying bacteria), which were less evident in MABA and effluent. In this sense, such bacteria might be excluded from MABA due to their good settling properties and the presence of antimicrobial peptides. Microalgae-bacteria treatment systems steadily reduced ARGs from wastewater during operation time, using sunlight as the energetic driver, making them ideal for use in LMIC wastewater treatment applications.

Monitoring of SARS-CoV-2 RNA in wastewater: A surveillance tool to foresee infection's evolution in the Mexican Caribbean.

The study aims to determine SARS-CoV-2 RNA in sewage of Cancun wastewater treatment plants, the main touristic destination of Mexico, and to estimate the infected persons during the sampling period. SARS-CoV-2 RNA traces were detected in the inlet of the five plants during almost all the sampling months. However, there is no presence of SARS-CoV-2 RNA traces in the effluent of the five WWTPs during the study period. ANOVA analysis showed differences in the concentrations of RNA traces of SARS-CoV-2 between the sample dates, but no differences were found from one WWTP to another. Estimated infected individuals by Markov chain Monte Carlo simulation are higher (between 77% and 91%) than the cases reported by the health authority. Wastewater monitoring and the estimation of infected individuals are a helpful tool, because estimation provides early warning signs on how broadly SARS-CoV-2 is circulating in the city, and led to the authorities to take measures wisely. PRACTITIONER POINTS: There is no presence of SARS-CoV-2 RNA traces in the effluent of the facilities, suggesting the effectiveness of treatment. Surveillance of viral RNA concentrations at treatment plants revealed presence in the influent of five plants Estimated infected individuals by MCMC simulation are higher than cases reported by health authority Environmental surveillance approach in wastewater influent is helpful to identify the clusters and to take informed decisions.

Loop-mediated isothermal amplification-based electrochemical sensor for detecting SARS-CoV-2 in wastewater samples.

The current pandemic COVID-19 caused by the coronavirus SARS-CoV-2, has generated different economic, social and public health problems. Moreover, wastewater-based epidemiology could be a predictor of the virus rate of spread to alert on new outbreaks. To assist in epidemiological surveillance, this work introduces a simple, low-cost and affordable electrochemical sensor to specifically detect N and ORF1ab genes of the SARS-CoV-2 genome. The proposed sensor works based on screen-printed electrodes acting as a disposable test strip, where the reverse transcription loop-mediated isothermal amplification (RT-LAMP) reaction takes place. Electrochemical detection relies upon methylene blue as a redox intercalator probe, to provide a diffusion-controlled current encoding the presence and concentration of RT-LAMP products, namely amplicons or double-stranded DNA. We test the performance of the sensor by testing real wastewater samples using end-point and time course measurements. Results show the ability of the electrochemical test strip to specifically detect and quantify RT-LAMP amplicons below to ~ 2.5 × 10-6 ng/µL exhibiting high reproducibility. In this sense, our RT-LAMP electrochemical sensor is an attractive, efficient and powerful tool for rapid and reliable wastewater-based epidemiology studies.

Prevalence of chronic musculoskeletal pain among active and retired military personnel: a systematic review protocol.

OBJECTIVE: The objective of this review is to assess the prevalence of musculoskeletal chronic pain among active and retired members of military forces and to characterize potential factors that could influence the frequency of musculoskeletal chronic pain. INTRODUCTION: Inherent to military occupations is a diverse source of occupational hazards that affect the well-being of individuals at any stage of their military career (active and retired). Chronic pain may result from the continuous exposure to physically demanding tasks and other risks. Moreover, chronic pain has been associated with other comorbidities, including mental health conditions. INCLUSION CRITERIA: Scientific papers in French or English reporting on chronic pain derived from a musculoskeletal cause in active and retired military personnel will be considered. There will be no restriction on participants' country, age, or length of service. METHODS: The published literature will be identified by exploring biomedical, pharmacological, and physiology bibliographic databases. The unpublished literature will be located through the search of thesis and gray literature repositories. This review will follow the condition-context-population approach and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The extracted data will include any detail about the anatomic location, diagnosis, types of studies, and risk factors. The review will follow JBI methods of critical appraisal, data extraction, and data synthesis for reviews containing prevalence data. If enough evidence is found, meta-regression analysis will performed, otherwise a narrative review will be completed. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO CRD42020153704.

Surveillance of SARS-CoV-2 in sewage and wastewater treatment plants in Mexico.

The SARS-CoV-2 virus causing COVID-19 is spread in sewage by the stool of infected individuals, and viral material in sewage can be quantified using molecular tools. This study aimed to monitor the presence of SARS-CoV-2 RNA in sewage in Mexico based on RdRP, S, and N gene analysis. The influent, effluent, and activated sludge from two domestic wastewater treatment plants (WWTP) were evaluated from the early stage of the epidemic to July 2020. Additionally, sampling points in sewer systems were examined, comparing two different RNA-concentration methods: centrifugal ultrafiltration and adsorption-based methods. The adsorption method resulted in RNA titration that was two orders of magnitude higher than with ultrafiltration (up to 3.38 log10 copies RdRP gene/mL of sewage). The surveillance of SARS-CoV-2 RNA in the influent of two WWTP correlated with the cumulative COVID-19 cases in Queretaro city. The higher RNA level in secondary sludge compared to influent suggests that viral RNA becomes concentrated in activated sludge. This result supports SARS-CoV-2 RNA removal in WWTP, where all effluent samples were negative for virus quantification. This work proves that wastewater-based epidemiology is a very valuable tool in developing countries where diagnostic tests for COVID-19 are limited.

Two rTMS sessions per week: a practical approach for treating major depressive disorder.

INTRODUCTION: Depression is one of the leading causes of disability in the world, and a disease that contributes greatly to the global burden of disease. Repetitive transcranial magnetic stimulation (rTMS) has proven to be a well-tolerated, effective treatment for depression. The present study was designed to evaluate the efficacy of an rTMS treatment scheme with a fewer number of sessions per week. METHODS: In total 91 adult university students with major depressive disorder (MDD). This was a double-blind, randomized clinical trial in which 15 sessions of rTMS were given to each one of two treatment groups made up of adults with active MDD. One treatment group received two sessions per week, the other received five. The study protocol included their respective sham rTMS groups. The patients who received active rTMS also participated in a follow-up procedure that consisted of two sessions of active rTMS per month for three more months. RESULTS: Measurements by the Hamilton Rating Scale for Depression (HAMD) showed that the groups which received active rTMS had higher percentages of antidepressant response at 96 and 95.5% for five and two sessions/week, respectively, compared to the sham rTMS groups: 27.3 and 4.5% for five and two sessions/week, respectively. Observations at the end of the 3-month follow-up phase showed that the improvements in HAMD scores were maintained in both groups. CONCLUSION: This study contributes to demonstrating that rTMS with a more practical schedule of two sessions/week is an effective antidepressant treatment that could be considered the first choice for managing symptoms of depression.

Approaches applied to detect SARS-CoV-2 in wastewater and perspectives post-COVID-19.

Currently, SARS-CoV-2 has been detected in the influent of wastewater treatment plants (WWTP), pumping stations, manholes, sewer networks and sludge of WWTP and facilities of countries as France, Spain, Italy, Netherlands, United States, Australia, Ecuador, Brazil and Japan. Although this virus has been detected in the wastewater streams, there is no robust method for its detection and quantification in wastewater. This review compiled and analyzed the virus concentration approaches applied to detect the SARS-CoV-2, besides to provide insights about the methodology for viral concentration, limit of detection, occurrence, persistence, and perspectives post-COVID-19 related with the implications of the virus presence in wastewater. The SARS-COV-2 detection in wastewater has been related to virus concentration methods, which present different recovery rates of the virus. The most used viral concentration methods have been the polyethylene glycol (PEG) for precipitation of viral material and the ultrafiltration at molecular weight level. After viral concentration, the detection and quantification of SARS-COV-2 in wastewater are mainly via quantitative reverse transcription polymerase chain reaction (RT-qPCR), which is the clinical assay adapted for environmental purposes. Although in some experiments the positive control during RT-qPCR is running a surrogated virus (e.g., Mengovirus or Dengue virus), RT-qPCR or reverse transcription droplet digital PCR (RT-ddPCR) targeting the gene encoding nucleocapsid (N1, N2 and N3) of SARS-COV-2 are highly recommended to calculate the limit of detection in wastewater samples. Current results suggest that a rigorous methodology to elucidate the positive cases in a region from genomic copies in wastewater is needed.

Continuous anaerobic oxidation of methane: Impact of semi-continuous liquid operation and nitrate load on N2O production and microbial community.

This work proves the feasibility of employing regular secondary activated sludge for the enrichment of a microbial community able to perform the anaerobic oxidation of methane coupled to nitrate reduction (N-AOM). After 96 days of activated sludge enrichment, a clear N-AOM activity was observed in the resulting microbial community. The methane removal potential of the enriched N-AOM culture was then studied in a stirred tank reactor (STR) operated in continuous mode for methane supply and semi-continuous mode for the liquid phase. The effect of applying nitrate loads of ∼22, 44, 66, and 88 g NO3- m-3 h-1 on (i) STR methane and nitrate removal performance, (ii) N2O emission, and (iii) microbial composition was investigated. Methane elimination capacities from 21 ± 13.3 to 55 ± 12 g CH4 m-3 h-1 were recorded, coupled to nitrate removal rates ranging from 6 ± 3.2 to 43 ± 14.9 g NO3- m-3 h-1. N2O production was not detected under the three nitrate loading rates applied for the assessment of potential N2O emission in the continuous N-AOM process (i.e. ∼22-66 g NO-3 m-3 h-1). The lack of N2O emissions during the process was attributed to the N2O reducing capacity of the bacterial taxa identified and the rigorous control of dissolved O2 and pH implemented (dissolved O2 values ≤ 0.07 g m-3 and pH of 7.6 ± 0.4). Microbial characterization showed that the N-AOM process was performed in absence of putative N-AOM archaea and bacteria (ANME-2d, M. oxyfera). Instead, microbial activity was driven by methane-oxidizing bacteria and denitrifying bacteria (Bacteroidetes, α-, and γ-proteobacteria).

Thermophilic biogas production from microalgae-bacteria aggregates: biogas yield, community variation and energy balance.

Biogas production through anaerobic mesophilic digestion is the most straightforward biofuel production route integrated into microalgae-bacteria wastewater treatment plants. Improvement of this biofuel route without adding pretreatment units is possible through the temperature increase. This paper presents a comprehensive evaluation of the transitory effect of different temperatures (35 °C and 55 °C) and hydraulic retention times (HRT) of 15 and 30 d on the long-term methane production using non-pretreated microalgae-bacteria aggregates as a feedstock. The thermophilic transition from mesophilic inoculum adapted to microalgae-bacteria aggregate increased 1.7-fold the methane production (0.41 m3CH4 kgVS-1) at HRT of 30 d. A substantial decrease in the microbial community's diversity present in the anaerobic reactor was observed when thermophilic conditions were applied, explaining the long adaptation period needed. The increase of the operative temperature condition promotes changes in the dominance pathway of methanogenesis from hydrogenotrophic to acetolactic. The energy balance assessment showed a positive net energy ratio when the digester was operated at an HRT of 30 d. A maximum net energy ratio of 1.5 was achieved at mesophilic temperature. This study demonstrated, based on experimental data, that microalgal digestion with an HRT of 30 d favors energy self-sustainability in microalgal wastewater treatment plants.

A review on the factors influencing biohydrogen production from lactate: The key to unlocking enhanced dark fermentative processes.

Dark fermentation (DF) is one of the most promising biological methods to produce bio-hydrogen and other value added bio-products from carbohydrate-rich wastes and wastewater. However, process instability and low hydrogen production yields and rates have been highlighted as the major bottlenecks preventing further development. Numerous studies have associated such concerns with the inhibitory activity of lactate-producing bacteria (LAB) against hydrogen producers. However, an increasing number of studies have also shown lactate-based metabolic pathways as the prevailing platform for hydrogen production. This opens a vast potential to develop new strategies to deal with the "Achilles heel" of DF - LAB overgrowth - while untapping high-performance DF. This review discusses the key factors influencing the lactate-driven hydrogen production, paying particular attention to substrate composition, the operating conditions, as well as the microbiota involved in the process and its potential functionality and related biochemical routes. The current limitations and future perspectives in the field are also presented.

Innovative Control of Biofilms on Stainless Steel Surfaces Using Electrolyzed Water in the Dairy Industry.

Biofilms on food-contact surfaces can lead to recurrent contamination. This work aimed to study the biofilm formation process on stainless steel plates used in the dairy industry: 304 surface finish 2B and electropolished; and the effect of a cleaning and disinfection process using alkaline (AEW) and neutral (NEW) electrolyzed water. Milk fouling during heat processing can lead to type A or B deposits, which were analyzed for composition, surface energy, thickness, and roughness, while the role of raw milk microbiota on biofilm development was investigated. Bacteria, yeasts, and lactic acid bacteria were detected using EUB-338, PF2, and Str-493 probes, respectively, whereas Lis-637 probe detected Listeria sp. The genetic complexity and diversity of biofilms varied according to biofilm maturation day, as evaluated by 16S rRNA gene sequence, denaturing gradient gel electrophoresis, and fluorescence in situ hybridization microscopy. From analysis of the experimental designs, a cleaning stage of 50 mg/L NaOH of AEW at 30 °C for 10 min, followed by disinfection using 50 mg/L total available chlorine of NEW at 20 °C for 5 min is a sustainable alternative process to prevent biofilm formation. Fluorescence microscopy was used to visualize the effectiveness of this process.

Standardized protocol for determination of biohydrogen potential.

Biohydrogen production potential (BHP) depends on several factors like inoculum source, substrate, pH, among many others. Batch assays are the most common strategy to evaluate such parameters, where the comparison is a challenging task due to the different procedures used. The present method introduces the first internationally validated protocol, evaluated by 8 independent laboratories from 5 different countries, to assess the biohydrogen potential. As quality criteria, a coefficient of variation of the cumulative hydrogen production (H max) was defined to be <15 %. Two options to run BHP batch tests were proposed; a manual protocol with periodic measurements of biogas production, needing conventional laboratory materials and analytical equipment for biogas characterization; and an automatic protocol, which is run in a device developed for online measurements of low biogas production. The detailed procedures for both protocol options are presented, as well as data validating them. The validation showed acceptable repeatability and reproducibility, measured as intra- and inter-laboratory coefficient of variation, which can be reduced up to 9 %.

Molecular variability of Streptococcus uberis isolates from intramammary infections in Canadian dairy farms from the Maritime region.

The primary objective of this study was to explore the variability of Streptococcus uberis (S. uberis) isolates by extracting multilocus sequence typing (MLST) data from whole-genome sequencing. The secondary objective was to determine the distribution of the phenotypic antimicrobial resistance (AMR) and the associated AMR genes as well as the virulence gene profiles among sequence types (STs). Sixty-two isolates were recovered from 16 herds in 3 Canadian Maritime Provinces: New Brunswick (14.5%), Nova Scotia (48.3%), and Prince Edward Island (37.1%). Of these, 9, 30, and 23 were recovered from post-calving, lactational samples, and post-mastitis samples, respectively. These 62 S. uberis isolates belonged to 34 STs; 11 isolates were typed to 9 known STs and 51 isolates were classified as one of 25 new STs. Thirteen isolates were part of major clonal complexes (CCs). Post-mastitis isolates contained 10 unique STs, lactational isolates contained 11 unique STs, and post-calving isolates had 3 STs. Each farm had only 1 isolate that was a unique ST except for STs 233, 851, 855, 857, 864, and 866, which were found in multiple cows per herd on more than one farm. ST851 and ST857 were found in each of the 3 sample types, with ST857 found in cows from all 3 Maritime provinces. These results indicate that S. uberis is a diverse non-clonal pathogen with specific STs residing in clonal clusters, carrying multiple AMR genes and virulence, with a diverse phenotypic AMR.

L'objectif premier de la présente étude était d'explorer la variabilité d'isolats de Streptococcus uberis en extrayant les données de typage génomique multilocus (MLST) du séquençage du génome entier. L'objectif secondaire était de déterminer la distribution des phénotypes de résistance antimicrobienne (AMR) et les gènes d'AMR associés ainsi que les profils des gènes de virulence parmi les types de séquence (STs). Soixante-deux isolats ont été obtenus de 16 troupeaux dans trois provinces maritimes canadiennes : le Nouveau-Brunswick (14,5 %), la Nouvelle-Écosse (48,3 %), et l'Ile-du Prince-Édouard (37,1 %). Parmi ces isolats, 9, 30, et 23 ont été obtenus d'échantillons post-vêlage, en lactation, et post-mammite, respectivement. Ces 62 échantillons appartenaient à 34 STs; 11 isolats ont été typés comme appartenant à 9 STs connus et 51 isolats ont été classifiés dans un des 25 nouveaux STs. Treize isolats faisaient partis de complexes clonaux majeurs (CCs). Les isolats post-mammite contenaient 10 STs uniques, les isolats de la période de lactation contenaient 11 STs uniques, et ceux de la période post-vêlage avaient 3 STs. Chaque ferme n'avait seulement qu'un isolat qui avait un ST unique sauf pour les STs 233, 851, 855, 857, 864, et 866 qui ont été retrouvés chez plusieurs vaches par troupeau sur plus d'une ferme. Les ST851 et ST857 ont été trouvés dans chacun des trois types d'échantillons, avec ST857 retrouvé dans des vaches des trois provinces maritimes. Ces résultats indiquent que S. uberis est un agent pathogène diversifié non-clonal avec des STs spécifiques résidant dans des groupements clonaux, arborant de multiples gènes de résistance antimicrobienne et de virulence, avec des phénotypes d'AMR variés.(Traduit par Docteur Serge Messier).